.container {
  width: 400px;
  height: 500px;
  border: 1px solid #000;
  margin: 0 auto;
  overflow: scroll;
  position: relative;
}
ul {
    list-style: none;
    margin: 0;
    padding: 0;
    

}
li{
    height: 50px;
    border: rgb(229, 11, 11) 1px solid;
    box-sizing: border-box;
    line-height: 50px;
    text-align: center;
}
.list-phantom {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
}
.list {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
}
